Cognitive Impairment in Schizophrenia, Bipolar & Autism

Neurological/neuropsychiatric disorders are often poorly described and poorly treated, but adult-onset conditions have historically been taken much more seriously and so the research is more advanced .  I find myself quite often looking at research on schizophrenia and bipolar; many of the same genes and metabolic dysfunctions common in autism show up in those conditions.

Many people really dislike the term Mental Retardation (MR), which is actually a very accurate descriptive term, meaning that someone is cognitively behind their peers.  Most lay people have no idea what Intellectual Disability (ID) means.

It is interesting that about 90% of people with schizophrenia and 50% of people with bipolar are cognitively behind their peers.  I suspect the figure for autism would also be about 90%, if someone measured it.  Most people with Asperger’s are not top of the class.

Only in extreme cases of being cognitively behind their peers, when their IQ is less than 70, does a person get diagnosed with MR/ID.

So the clinical diagnosis of MR/ID is just an arbitrary cut-off point.  The idea that if IQ is greater than 70 there is no cognitive deficit is entirely flawed.

It seems than in autism, as in schizophrenia and bipolar we should assume that cognitive dysfunction is present; the only question is how much and what to do about it.

Having treated the cognitive dysfunction(s), the person is then in a better place to compensate for the other dysfunctions they might have.

Even though the psychiatrists and psychologists will tell you that autism is all about the triad of impairments, I think they are missing the most important element, which is cognitive dysfunction.

As people with autism age, many find their symptoms associated with the above “triad of impairments” mellow.  The substantial minority who experience untreated flare-ups driven by inflammation caused by things like allergy, GI problems and even juvenile arthritis may not be so lucky.

I imagine that cognitive function in adulthood remains at the level it reached as a teenager.

Cognitive Function as the Therapeutic Target

Since many children with autism do eventually overcome many of their challenges in childhood, perhaps cognitive function really should be given a higher priority in treatment and research.

Many caregivers and educators are mainly focused on minimizing bad/disruptive behaviors (and bruises) rather than the emergence of good behaviors and learning.  This is sad but true.

As the child matures, in many cases these bad/disruptive behaviors may fade without any clever interventions.

So an intervention that stops stereotypy in a toddler, which was blocking learning, may have very much less impact in an adolescent.  Or at least the impact may be much less obvious.

I remember reading about a parent with two children with Fragile-X who was very upset when the Arbaclofen trials were halted, since her kids had responded well.  But two years later in another article it was clear that things were going fine without Arbaclofen.  The son whose violence towards his mother had been controlled by Arbaclofen, was no longer aggressive.  He continued to suffer cognitively, being a male with Fragile-X, the sister was much less affected  (females with fragile X syndrome have two X chromosomes and only one of the chromosomes usually have an abnormal gene, so usually females are less affected).   

The advantage of using cognitive function as a target is that it is much easier to measure than subjective behavioral deficits.  For the majority of people it is likely to be the most important factor in their future success and well-being.

In the substantial minority of cases where there are seizures and/or factors causing autism flare-ups, the behavioral deficits may remain undiminished into adulthood.  These people would also benefit from maximized cognitive function.

Cognitive Deficit in Schizophrenia & Bipolar (BPD)

To most lay people schizophrenia is characterized by abnormal social behavior and failure to recognize what is real. Common symptoms include false beliefs, unclear or confused thinking, hearing voices, reduced social engagement and emotional expression, and a lack of motivation. People often have additional mental health problems such as major depression, anxiety disorders, or substance use disorder. Symptoms typically come on gradually, begin in early adulthood, and last a long time.

Cognitive impairments and psychopathological parameters in patients of the schizophrenic spectrum.

  

Abstract

Cognitive impairment is a core feature of schizophrenia and it is considered by many researchers as one of the dimensional components of the disorder. Cognitive dysfunction occurs in 85% of schizophrenic patients and it is negatively associated with the outcome of the disorder, the psychosocial functioning of the patients, and non-compliance with treatment. Many different cognitive domains are impaired in schizophrenia, such as attention, memory, executive functions and speech. Nowadays, it is argued that apart from clinical heterogeneity of schizophrenia, there is probable heterogeneity in the accompanying neurocognitive dysfunction. Recent studies for cognitive dysfunction in schizophrenia employ computerized assessment batteries of cognitive tests, designed to assess specific cognitive impairments. Computerized cognitive testing permits for more detailed data collection (e.g. precise timing scores of responses), eliminates researcher's measurement errors and bias, assists the manipulation of data collected, and improves reliability of measurements through standardized data collection methods. The aims of the present study are: the comparison of cognitive performance of our sample of patients and that of healthy controls, on different specific cognitive tests, and the testing for possible association between patients' psychopathological symptoms and specific cognitive impairments, using the Cogtest computerized cognitive assessment battery. 71 male inpatients diagnosed with schizophrenia or other psychotic spectrum disorders (mean = 30.23 ± 7.71 years of age), admitted in a psychiatric unit of the First Department of Psychiatry, Athens University Medical School, Eginition Hospital (continuous admissions) were studied. Patients were excluded from the study if they suffered from severe neurological conditions, severe visual or hearing impairment, mental retardation, or if they abused alcohol or drugs.

Bipolar disorder, also known as bipolar affective disorder or manic depression, is a mental disorder characterized by periods of depression and periods of elevated mood. The elevated mood is significant and is known as mania or hypomania depending on the severity or whether symptoms of psychosis are present. During mania an individual feels or acts abnormally happy, energetic, or irritable. They often make poorly thought out decisions with little regard to the consequences. The need for sleep is usually reduced. During periods of depression there may be crying, poor eye contact with others, and a negative outlook on life

It also turns out that cognitive deficit is generally present in bipolar disorder (BPD).

Understanding Cognitive Impairments in Bipolar Disorder and Psychosis

  

“One area that Dr. Burdick is exploring is the frequency of neurocognitive impairment in BPD. Research shows that approximately 90 percent of schizophrenic patients suffer from cognitive deficits compared to only 40 to 60 percent of BPD patients. Understanding why certain patients develop significant cognitive difficulties while others do not is critical in optimizing patients’ quality of life, she says.”

Bipolar is probably not something you would connect with autism.  Being an observational diagnosis you would not tend to look at the biological underpinnings. The biological basis of both bipolar and schizophrenia are far better studied than autism and do significantly overlap with it.

In a recent post I looked at epigenetics and autism, when it comes to schizophrenia and bipolar the role of epigenetics is far more in the mainstream.

There is an approved epigenetic therapy (the HDAC inhibitor Valproate) for Bipolar mania and there is a clinical trial to improve cognitive function in schizophrenia using ather epigenetic therapy (the HDAC inhibitor Sodium Butyrate.)

Butyrate is also showed promise in a mouse model (D-AMPH) of Bipolar.

Sodium Butyrate For Improving Cognitive Function In Schizophrenia

Epigenetic mechanisms in schizophrenia

Effects of sodium butyrate on oxidative stress and behavioral changes induced by administration of D-AMPH

Conclusion

I think people should be more open to discuss cognitive deficits and not hide behind politically correct terminology.

It seems that in both bipolar and schizophrenia cognitive deficits are recognized to be at the core of the disorder, even though 99% will not have an IQ<70 and so not be labelled with MR/ID.

Autism therapies which clearly improve cognitive function, like Bumetanide and low-dose Clonazepam, should be promoted as such.  Clinical trials should measure the cognitive improvement separately from autism measures.  As the person ages I think the benefit will often be more noticeable/measurable cognitively than behaviorally.